Sieve frame



April 19, 1938.

L. E. SIMPSON SIEVE FRAME 2 Sheets-Shget 1 Filed May 12, 1936 INVENTOR. Law: E S/MPsa/v.

ATTORNEY8 Patented Apr. 19, 1938 UNITED STATES PATENT OFFICE- SIEVE FRAME Lowe E. Simpson, Cincinnati, Ohio Application. May 12, 1936, Serial No. 79,326

7 Claims.

My invention relates to devices for use in connection with sifting machinery in which a frame is employed with cloth or wire stretched over it, and its one object is to provide for a frame which has a fixed part and an expansible part, the expansible part being secured to the screening or fabric and adjustable in a simple fashion. In such a constructionthe dimensioned part of fixed nature could then be designed to correspond to a superimposed frame or the like,-and the adjustable part does not need to be in any definite position in order for the sieve frame to properly cooperate with the other parts, for example, in a sifting machine.

Among the objectives of my invention is the provision of simple clip devices which can be secured at any position that is convenient along the expansible element of the frame, and to pro- .vide for the simplest mode of attaching the screen cloth or other fabric to the said expansible elements, and to make the expansive elements readily replaceable.

As a feature of my invention is the further fact that by having a fixed frame portion, I am enabled to avoid the presence of any corners or joints which might open up upon adjustment of the screen cloth, thus permitting leakage, which is undesirable.

I accomplish my object by that certain con- .struction and arrangement of parts of which I "describe in the manner that follows, a single example. The novelty inherent in the structure will be set forth in the claims that follow.

In the drawings:

Fig. 1 is a side elevation of a sifting machine showing sieve screens and sieve frames in place.

Fig. 2 is a perspective of a sieve frame constructed in accordance with my invention.

Fig. 3 is a section on a larger scale showing a mode of assembly of sieve frames built in accordance with my invention, with other sieve frames and spacers in a clamped arrangement.

Fig. 4 is a perspective of my novel clip device.

I have shown as an example a sifting machine having a base I, frame of hollow box-like shape 2, and an operating device at 3. Within this device are illustrated two sieve frames 4 and 5, with a spacer 6 and a receiving box I held down in a frame 2, by means of clamps 8.

Referring next to the sieve frame itself, which of course may be adapted to a wide variety of uses, I provide a metallic frame consisting of section 9, tightly abutted at the corners as at l0, and forming a rectangular structure, in this instance mounted on a sub-frame ll of wood, by

means of screws [2. In detail these frame pieces which constitute the fixed frame portion hereto-' fore referred to, have upstanding webs [3 turned outwardly at [4 in a rounded conformation. The base 15 of metal sections is provided with an ini wardly bentupstanding tongue l6, preferably'extending the full length of the frame pieces in each instance, so that the clips may engage it at any point.

The metal clips are formed withupstanding portions I51 and tapped with threaded holes" 18' to receive abutment screws l9. In addition they have bases 20, with an upstanding ridge 21 to form a. channel, that receives the wooden strips 22 constituting the movable portion of the sieve frame". Theclips also have outwardly bent tongues. 23', which engage under the ridges IS on the fixed frame member permitting the clips to rock thereon.

The screen fabric 24 is laid over the combined structure of frame members and tacked as indicated at 25 to the wooden frame members. The screws of theclips are then turned in, abutting against. the upstanding. walls of the fixed frame members and tilting the clips and with them the 2 wooden frame members; The result is tostretch the fabric, while still leaving the upper edges of the fixed frame in abutment therewith,

A spring 25, may be mounted onthe outer edge of the base 20 of each clip, to engage the slot 26 in the adjusting screw for the clip, thus acting as a safety latch for the screw position.

The advantage of the arrangement described is obvious. The fabric may be stretched tight Without interfering with the fixed frame. The fixed frame is the dimensioned part of the structure so far as use of the sieve with other parts in a machine is concerned. The fixed frame is tight at the corners. The wooden members can be replaced, if broken. The clips are detachable and can be mounted on the wooden members in any location and in the desired number as to each wooden frame member. It is easy to adjust the tautness of the fabric at any time without disarranging any part of the sieve.

In the structure shown, I have provided for special spacers between sieve frames in a sifting machine or the like. Thus I have shown a frame 6, edged top and bottom with metal channels 3|. These channels have reentrant walls so that a rubber strip 32 can be forced into them and will remain in place.

When placed between two of my novel sieve frames, the rubber portion will lie over and abut against the screening or other fabric where it crosses the tops of the fixed frame members. This very tightly closes the space between frames against leakage, and as noted there can be no leakage through the corners of the fixed frame.

Where a hopper box is added at the top of a sifter, the same arrangement is made. Thus the rectangular box-like frame 21, is set into the main frame of the sifter, and held down in place over the assembly of sieve frames and spacers by means of any desired form of clamp 8. The lower edge of the frame 21 is fitted with a metal channel 28, which has mounted therein the rubber strips 29. Here again the placing of the metal channels is such that the rubber strips will abut against the screen fabric where it lies across the upper rounded edge of the fixed frame.

I have indicated ball supporting fabric 30 tacked to the under side of the wooden supports for the sieve frames. This, of course, is employed only in the ball type of sifter.

It will be apparentthat modifications within the principle of the structure now described, may lie within the inventive concept thereof, and I endeavor in my claims that follow to express this concept, Without in this specification describing alternative forms of parts. which occur to me.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: I

1. In combination for the purpose described, a fixed, metallic frame, Wooden frame members located exteriorly of the metallic frame, and clips engaging the wooden frame members, means on the frame engaged by the clips, means for adjusting the position of the clipsv with relation to the frame and screen fabric secured to the wooden frame members.

2. In combination for the purpose described, a fixed, metallic frame, wooden frame members located exteriorly of the metallic frame, and clips engaging the Wooden frame members, means on the frame engaged by the clips, means for adjusting the position of the clips with relation to the frame and screen fabric secured to the wooden frame members, said fixed frame having an upstanding portion which abuts the under side of the fabric in the several adjusted positions of the Wooden frame members.

3. In combination for the purpose described, a fixed, metallic frame, wooden frame members located exteriorly of the metallic frame, and clips engaging the wooden frame members, means on the frame tiltably engaged by the clips, means for adjusting the position of the clips with relation to the frame and screen fabric secured to the wooden frame members.

4. In combination for the purpose described, a fixed, metallic frame, wooden frame members located exteriorly of the metallic frame, and clips engaging the wooden frame members, means on the frame tiltably engaged by the clips, means for adjusting the position of the clips with relation to the frame and screen fabric secured to the Wooden frame members, said fixed frame having an upstanding portion which abuts the under side of the fabric in the several adjusted positions of the wooden frame members.

5. In combination, a fixed frame element having an upstanding portion and a projecting base having a rib thereon, and a clip for securing another frame member in adjustable position with respect to the frame element comprising a base having a channel on its upper side for retention of the frame member, a rib on the under side of the base for engagement with the rib on the frame element, an upward projection of said clip, and an abutment screw in said upward projection and bearing against the upstanding portion of the frame element.

6. In a sifter assembly, the combination with a fixed frame, a sifting fabric, adjustable sifting fabric retaining frame elements exteriorly supported on said fixed frame, with the fabric extending across the tops of the fixed frame, thus defining by means of the fixed frame the location of the sifting fabric in the sifter assembly, and a second frame forming part of said assembly having about its under edge a rubber element dimensioned to abut against said fixed frame with the sifting fabric therebetween.

'7. In combination in an assembly of frames in a sifting machine, a frame element having sifting fabric overlying its upper edge and another frame element having metal channels secured about its lower edge and rubber abutment strips mounted in said channels, said channels and rubber abutment strips defining an outline which corresponds with the said upper edge of the said fixed frame and resting thereover.

' LOWE E. SIMPSON. 

